Effect of Hydroxypropylation on the Properties of White Yam (Dioscorea rotundata) Starch

Starch isolated from white yam (Dioscorea rotundata) was subjected to hydroxypropylation under different conditions. Corresponding increases were observed between the molar substitution (MS) and the volume of propylene oxide added to the reaction mixture. After hydroxypropylation, a slight reduction in the intensity of the peak at 2θ = 19.6° was observed and the doublet peak at 23.8°, which was present in native starch, was no longer seen. Hydroxypropylation enhanced the free swelling capacity (FSC) and solubility. Setback and retrogradation of native starch declined after hydroxypropylation. Turbidity of native starch paste and syneresis were higher with storage time. The results also indicate that enzymatic digestibility improved as the MS increased, while the reverse was observed for starch paste turbidity, syneresis, setback and retrogradation. This study presents relevant information that could strategically position D. rotundata starch and its hydroxypropylated derivatives for industrial applications.     

Some Physico-chemical Properties of Dioscorea Starch from Ethiopia

The chemical composition, amylose content and physio-chemical properties of dioscorea starch (Dioscorea abyssinica, Fam. Dioscoreaceae) from Ethiopia have been investigated. The proximate composition of the starch on dry weight basis was found to be 0.1% ash, 0.5% protein, 1.0% fat and 98.4% starch. The amylose content was 29.7%. Scanning electron microscopy (SEM) showed rounded granules. Particle size analysis revealed granule size distribution with a mean particle size of 29.2 μm. X-ray diffraction study showed a pattern that is typical of B-type with a distinctive maximum peak at around 17° 2 T. The moisture sorption pattern, the swelling power and the solubility values were determined and found to be lower than potato starch. Brabender viscosity curves of 6% starch paste showed a peak viscosity of 781 BU. The breakdown and retrogradation of dioscorea starch were 25 and 501 BU, respectively. DSC parameters of starch-water mixture (1:2) exhibited an onset temperature (T_o) of 64.2°C, a peak temperature (T_p) of 68.2°C and an endset temperature (T_e) of 74.8°C. The enthalpy of gelatinization (ΔH) was 19.2 mJmg⁻¹.     

慈姑淀粉的性质研究

研究了慈姑淀粉性质,结果发现:慈姑淀粉粒多呈圆形,少数椭圆形,粒径范围为4～25μm,平均粒径10μm,X-射线衍射呈C型结晶图样。DSC法测得慈姑的起始糊化温度To=52.330℃,峰值温度TP=68.226℃,终止温度Tc=77.280℃。快速黏度测定仪测得慈姑淀粉的峰值黏度为2363.00mPa.s,最低黏度为1756.00mPa.s。55℃以下,慈姑淀粉的溶解度与膨润力低,糊化后溶解度与膨润力大大提高。与玉米淀粉、木薯淀粉和莲藕淀粉相比,慈姑淀粉糊透明度较低,冻融稳定性较强。     

Physicochemical Characterization and Application of Yam (Dioscorea cayenensis‐rotundata) Starch as a Pharmaceutical Excipient

Yam starch from Dioscorea cayenensis‐rotundata complex was isolated and characterized by scanning electron microscopy (SEM), particle size analysis, X‐ray diffraction, differential scanning calorimetry (DSC), compaction and rheology, and compared to maize (Zea mays) and potato (Solanum tuberosum) starches. Yam starch exhibited a log‐normal distribution of flattened ovoid shaped granules with a mean particle size of 25 µm. X‐ray diffraction showed a C‐type crystalline pattern with the degree of relative crystallinity estimated to be 34%. DSC analysis suggests that the crystalline regions in yam starch are thermally and structurally more stable as in maize and potato. Irrespective of the relative humidity (39, 67, 78% R.H.) yam starch exhibited higher moisture uptakes than maize starch and lower than potato. Intermediate values of swelling power and amylose leaching were obtained for yam as compared to maize and potato. Compaction properties of yam and potato starches were similar. However, compacts from yam presented a relatively lower tensile strength. Aqueous starch systems (4%) of yam and maize starches showed analogous shear‐thinning (pseudo‐plastic) behavior suitably described by the power‐law model. These results support the potential use of yam starch as excipient comparable to potato starch in pharmaceutical solid forms and as thickening agent similar to maize in pharmaceutical applications.     

橡子淀粉性质的研究

近年来国内开始发展用较先进的机械分离设备和方法 ,以野生橡子为原料加工的淀粉 ,深受外商青睐。本文较系统地研究了橡子淀粉的颗粒、糊等方面的性质 ,结果表明 ,其颗粒粒径较小 ,平均值为 9 2 μm ,结晶结构属C型 ,直链淀粉含量 2 0 6% ,糊化温度为 5 9 5～68 0℃。橡子淀粉糊凝沉性稍弱于玉米淀粉 ,冷、热糊粘度稳定性很好 ,其他糊性质与玉米淀粉相似     

羧甲基淀粉糊性质的研究

本文对羧甲基淀粉糊性质进行了详细的研究，包括糊的冷热粘度稳定性、凝沉性、冻融稳定性、透明度、ｐＨ值和介质（蔗糖，氯化钠）对糊粘度性质的影响。结果表明，淀粉经过羧甲基化后，糊的热粘度稳定性大为降低，冷粘度稳定性增加；在ｐＨ３．５～８．５范围内，有较好的耐酸碱稳定性；１０％蔗糖对糊粘度性质影响不明显，添加氯化钠会使糊化温度升高，峰值粘度降低，凝沉性增大；羧甲基淀粉具有易糊化，糊凝沉性低，冻融稳定性好和透明度高的优良性质。     

玉米抗性淀粉的制备及其性质的研究

对玉米抗性淀粉的制备工艺进行了研究,确定了最佳的制备工艺:淀粉调乳(浓度2 5 % ,pH值8 0 )→预糊化→压热处理(12 0℃,30min)→冷却→低温静置(4℃,2 4h)→提纯。按该工艺制备RS ,其产率可达10 4 7%。研究了玉米抗性淀粉的性质,包括抗酶解能力、对普通淀粉黏度特性的影响、吸水能力及微观颗粒形貌。     

马铃薯羧甲基淀粉糊化特性研究

对马铃薯羧甲基淀粉糊性质进行了详细的研究,包括不同取代度羧甲基淀粉糊化温度,糊的冻融稳定性、透明性、抗霉生长能力及温度、浓度、回旋速度、pH值和介质对羧甲基淀粉糊粘度性质的影响。结果表明,马铃薯羧甲基淀粉具有低温易糊化,糊凝沉性弱,冻融稳定性好,抗霉能力强和透明度高的优良性质。氯化钠及钙离子对马铃薯羧甲基淀粉粘度性质有较大的影响。     

芋头淀粉糊的粘度性质

研究了芋头淀粉糊在不同质量分数、pH值以及不同蔗糖、食盐、明矾、硼砂添加量的条件下,Micro Visco-Amylo-Graph粘度曲线的变化情况,与马铃薯、木薯、玉米淀粉糊的粘度性质进行比较,为进一步了解芋头淀粉的特性及应用开发提供了一定的理论依据.     

羟丙基——磷酸单酯复合变性淀粉的制备及特性研究

主要研究了制备羟丙基-磷酸单酯复合变性玉米淀粉的最佳工艺条件，并测试了其主要特性。试验结果表明，羟丙基-磷酸单酯复合变性淀粉既克服了单一变性淀粉的弱点，又保留了其优点。其淀粉糊的特性有了明显改善，尤其是淀粉糊的透明度、冻融稳定性、蔗糖溶液的影响以及对蛋白发泡体系的影响等方面有了较为显著的改观。     

山药淀粉提取工艺的研究

以石灰水为浸泡剂,采用稀碱法从山药中提取淀粉,研究了pH值、液固比、浸泡时间、沉降时间对淀粉产率的影响,并用正交试验确定了山药淀粉制备的最佳工艺。试验结果表明,山药淀粉的最适宜制备工艺条件为：pH值8,液固比5,浸泡时间3h,沉降时间4h。     

Studies on Rye Starch Properties and Modification. Part I: Composition and Properties of Rye Starch Granules

Rye is considered as a potential raw material for starch industry. Starting from a survey of technical procedures of isolating starches from rye-flour and -grits investigations will be reported, which were performed on pilot plant- and laboratory-isolated rye starches. The present paper deals with its granule appearance and composition. A distribution of granule size between small granules (⩽ 10 μ − 15%) and large granules (⩾ 11 … ⩽ 40 μ − 85%) is typical for the totality of the starches. Differing distributions depend on the conditions of isolation: the entity of starch containing samples resulted from the laboratory procedures under investigation. Large-granule starch preparations were isolated in the pilot plant: the centrifuge-overflow contains the small-granule fraction which is high in impurities. Granule crystallinity amounts to 16%. The crystalline component - like in wheat and triticale starches - consists predominatly of A-polymorph - with up to 9% of the B-type. The isotherms of water exchange are of the cereal type. The contents of minor constituents largely relate to the small granule fraction which assembles the majority of crude protein, pentosans and lipids, which are difficult to remove

1 Large granule samples may be produced in high purity (⩽ 0,2% crude protein)

. Lipid components in all fractions influence the results of linear chain-iodine interactions and they must be removed to proceed from apparent to absolute polysac-charide indices. The absolute amylose contents amount to ∼ 25% for large granule samples and to 20–21% for small granule samples. The average chain-length of iodine binding helical regions was determined with 220–240 AGU.     

Studies on the Physical and Chemical Properties of Kiwi Fruit Starch

The kiwi fruit starch consisted of small round granules with an average size of 5.5μ, and was composed of 14.4% moisture, 0.17% crude protein, 0.11% lipid and 0.14% ash. The phosphorus, content was 25.5 mg/100g, which was the highest concentration of the minerals. The amylose content was 10.8% and the X-ray diffraction pattern was B-type. The gelatinization temperature, obtained by DSC measurement, was 72°C. The properties of the fully gelatinized form and the low degree of retrogradation were observed by ¹³C-NMR analysis. Free fatty acids detected in the lipid component of the starch were oleic, palmitic, linolenic, linoleic, and stearic acids.     

Physicochemical Properties and Starch Digestibility of Autoclaved-Cooled Water Yam (Dioscorea alata L.) Flour

Water yam (Dioscorea alata L.) is suitable for resistant starch high flour because of its high amylose content. The purple, yellow, and white water yams were treated by autoclaving and cooling with one, two, and three cycles to obtain resistant starch. Water yam tubers were cooked in an autoclave for 15 min, and then cooled prior to drying. Autoclaving–cooling of water yams decreased protein, fat, dietary fiber, water soluble polysaccharide, dioscorin, and diosgenin but increased amylose and sugar. The treatments significantly raised resistant starch and reduced in vitro starch digestibility that depended on water yam types, and affected starch granule morphology.     

甘薯精白淀粉和变性淀粉的研制及性能的研究

本文总结了甘薯精白淀粉及磷酸淀粉、可溶性淀粉、氧化淀粉等变性淀粉研制的最佳工艺条件，并对它们的理化特性进行了研究，为食品、轻纺、建筑等行业部门展示了广阔的应用前景。     

Studies on the Physico-chemical Properties of the Starch of Euryale ferox

The physico-chemical properties of starch isolated from the seeds of Euryale ferox have been investigated mainly by methylation studies, periodate experiments, absorption measurements, and viscosity measurements. Starch was fractionated into amylose and amylopectin by precipitation technique. The average length of unit chain in amylose and amylopectin was found to be 22 and 380 glucose units, respectively. Starch contains 25% amylose as determined by potentiometric titrations. Other properties of starch, amylose and amylopectin have been described in the present paper.     

小麦氧化-酯化淀粉的制备及其性质的研究

以醋酸酐为酯化剂,对小麦氧化淀粉进行酯化,研究酯化程度与反应条件的关系,测定粘度性质和结构特征.研究表明,反应体系pH、醋酸酐用量和氧化淀粉氧化程度的影响比较大.淀粉经氧化-酯化复合变性后,颗粒受到了更大程度的破坏,存在明显的酯羰基;复合变性后的淀粉更易糊化,糊的粘度有所降低,稳定性更好.     

交联微孔淀粉基本性质的研究

微孔淀粉是一种功能材料。文中运用电子显微镜、X-衍射、布拉班德粘度仪等分析仪器对交联微孔淀粉颗粒形态、晶体结构、理化特性、糊化特性进行研究。结果表明淀粉经交联、酶等处理后影响到颗粒表面及内部,但未影响到晶体结构;交联微孔淀粉的孔径、溶解度、溶胀度及吸水能力和吸油能力均明显改善,同时提高了淀粉的结构性能。证明了用先交联后微孔化处理的方法改善微孔淀粉的结构强度和吸附功能是可行的。